System is DragonFly BSD, xserver 1.4.0 and intel driver fresh 2.2 branch. DRI is fresh git from git://ww2.fs.ei.tum.de/~corecode/git/drm.git (DragonFly port is not yet submitted to upstream), mesa 7.0.2.
Server crashes while I move glxgears window. It might take some seconds, but is reproduceable 100%. It doesn't happen with DRI/EXA (although there is different crash, but it can't be triggered with glxgears). X is restarted after crash, but it isn't able to start any more - I have to reboot machine. Logs/conf/backtraces are from Thinkpad X61s laptop with 965GM chip, but the same happens in desktop with 965Q chip as well.
Backtrace isn't always the same, but the pattern is.

Created attachment 13611[details]
backtrace.txt
Although I'm afraid that it's already consequence, there is one of backtraces I get from X core. The patter is always the same, but there might be "... ProcPolyLine(); DamageDamageRegion(); cwPolylines(); XAAPolylinesFallback(); I830Sync(); ..." sequence in it.